Method and apparatus for conditioning air



July 25, 1933. H. o. FoRREsT Er AL I METHOD AND APPARATUS FOR CONDITIONING AIR Filed Sept. 18. 1931 Patented July 25, 1933 UNITED STATES PATENT OFFICE v HENRY O. FORREST, OF WEST ENGLEWOOD, AND LEE VAN HORN, OF ELIZABETH,

i NEW JERSEY METHOD A ND APPARATUS FOR CONDITIONING AIR Application filed September 18, 1931. Serial No. 563,596.

This invention relates to air nconditioning and more particularly to a method and apparatus for conditioning air for small rooms and chambers usually occupied by a small number of people and only for a portion of the day.

In dwelling houses, office buildings and the like, the need for conditioning air for the health and comfort of occupants of the rooms A in such buildings, exists only for a portion of the day. By virtue of this fact, it is unnecessary to provide a large and expensive device capable of continuously conditioning air.

According to our invention, we provide a method of conditioningl air and apparatus for carrying out the method'which will impart to air being conditioned desired characteristics of temperature and humidity for a portion of the day Without reactivation of the conditioning medium. In one embodiiment of our invention we condition air first by contacting it by a dehydrating fluid such as calcium chloride or lithium chloride brine which will dehumidify the air to a relative humidity lower than that necessary for comfort. The next step in conditioning the air is to contact the air with a humidifying fluid sprayed therethrough and rehumidify it to the degree that istics of. humidity which, for that particular temperature, places the air within the healthful comfort range.

In absorbing water from the air, the temperature of the dehydrating fluid is Aincreased. For this reason, we provide a cooled surface to contact the dehydrating fluid as 4it circulates through the system. By absorbing the heat resulting from the absorption of water, the dehydrating step is carried on without an increase in air temperature so that when the humidifying step ,is eected, the temperature of the air will be lowered. From the foregoing discussion it is apparent that We are able to dehumidity and cool the air to place it within the healthful comfort range without the use of refrigerants in the usual meaning, of the term.

` At the end of a period of time and when the rooms cease toybe occupied .by people so imparts to the air character-` that it is unnecessary to continue the conditioning of air, we shut down the air conditioning system and regenerate the dehydrating fluid. This regeneration process when a dehydrating liquid such as calcium chloride brine is used includes heating the liquid to about 140 F. and spraying it through the dehumidifying chamber as done during the air conditioning process. lVhile doing thus, a blast of air is forced through the fluid and since the fluid is at a high temperature, it heats the air so that it will absorb water from the fluid and by so doing, bring it to a desired degree of concentration. The third step of this intermittent process merely involves the circulation of a cooling fluid, such as water through cooling coils which contact the regenerated dehydrating fluid and bring its temperature back to the desired degree of coolness. p I

A primary object of our invention is to condition air and regenerate the conditioning medium intermittently.

Another object of the invention is to provide a compact air conditioning device capable of successively conditioning air and regenerating the conditioning medium.

Other objects will be apparent to those skilled in this particular art from the description in the specification in connection with the drawing in which:

' The figure is a schematic layout of an apparatus adapted to intermittently ycondition air and regenerate the conditioning medium.

In the embodiment of the invention which has been chosen for the purposes of illustration, and referring now to the drawing, there is shown a dehydrating chamber 10 in the upper portion of which is located a spray member 11. A blower 12 has an inlet portion 13 which through a damper controlled fitting 14 draws fresh air from the atmosphere through a duct 15 and air from a room (not shown) through a duct 16 and forces it into the chamber 10, through a duct.19. A pair of suitable bafiie members 17 and 18 are located in the lower portion of the chamber 10 and disposed therebetween are a plurality of cooling coils 20.

An air outlet duct 21 is Vconnected to the" chamber 10, on the side opposite the air in- -let 19, and is ,adapted to carry theair which has been treated in the chamber 10 to a humidifying chamber 25,. A Trtting 22 is located in the duct 21 and has a duct 23 leading to the vatmosphere and which is here shown at right angles to the duct 21 that connects the chambers 10 and 25. A suitable damper 24 is located in the duct 23 and a similar damper .1g 26is located in the duct portion 21 intenmediate of the fitting 22 and the chamber 25.v

Disposed below the chamber is a tank 30 which is connected to the lower portion of the chamber 10 by a pipe 31. A pipe 32 connects the lower portion of the tank 30, through a pump 33 and pipe 34, with the spray member 11, and with pump 33 as a iiow actuator, a liquid circulatory system is provided. A heater 35, which is here shown as an electric heater but which may also obpeople for aportion of the day, and referring' y especially to conditioning the room at a time of the year when both the te'm rature and humidity are too high forV conslderations of health and comfort, fresh air and air from 'the room being conditioned is forced into the chamber 10 by means of the blower 12 and there is contacted by a spray of suitable l.dehydrating fluid sprayed through the chamber by means of the member 11. This iuid `.may be any suitable solution having dehydrating powers, such as calcium chloride or zinc chloride brine, and in view of the process contemplated as a part of this invention; the tank 30, which acts as a storage base for this D solution, must be sujiiciently large to contain an ample quantity thereof. The fluid that has been sprayed through the air strikes the baiile 17 and flows across the cooling cgils 20 and then flows over an overflow portion ofthe baiiie 18 into the bottom of the chamber- 10, from where it is conducted through the pipe 31 to the tank 30. From the tank 30 the iuid flows through the pipe 32 to, the -pump 33 and then is forced through the pipe 34 back to the spray member 11.

,Y When this uid contactsthe air,fwhich under the conditions stated, has a high `aqueous content, it absorbs a quantity of watertherefrom, depending in amount upon the natuieand concentration of the dehydrating solution and the length of time of contact. In absorbing water from this air in a Q5 normal adiabatic process, the temperature of viously use, as a source of heat, either a gas ,the air or of the solution, or of both, will rise due to the release of heat by the absorption of Water and to make this process an isothermal one with respect to air, it is necessary to removevheat from the dehydrating 'solution and it is for this reason the cooling coils 20 and 36 are provided.'

The air within the chamber 10 that has been sprayed by the dehydrating fluid and dehumidied is conducted by the duct 21 to the chamber 25. In the chamber 25 this air is contacted by a suitable humidifying" solution, such as water, or if it is desired to remove carbon dioxide therefrom, a suitable solution of an alkali such as calcium hydroxide. This humidifying Huid is sprayed through the air by means of a spray member I27. The excess pf water or alkaline solution sprayed through the air falls to the bottom of the chamber 25 and'is removed therefrom by means of a pipe 28, which conducts it to a water pump 29,V by means of which it is returned to the spray member 27 through the pipe 28. The air, in absorbing water from the iuid sprayed therethrough falls inhtemperature so that the air which is discharged from the chamber. 25 and conducted b the duct 40 to the point of use, (not shown has been given the desired degree of humidity and temperature by means of extremely simple apparatus and without the use of refrigeration in the ordinary sense of the word.

Because of'the fact that in dehumidiying the air only a small amount of water is absorbed therefrom in proportion to the bulk of the dehydrating uid, and in the humidifying chamber only a relatively small amount of water is absorbed in imparting to the air the desired degree of humidiication, this conditioning process can be carried'on for a sub- 105 stantial portion of 24 hours without requiring reactivation of the dehydratinol Huid or renewal of the supply of humidlfying liquid. The cooling water supplied to the coils 36 and v 20 may be either a supply of ci water vwhen no available, and when the cost o water is not excessive, or in large installations, cooling water may be obtained from aclosed circulatory system utilizin a cooling tower, not

shown, and a pump, a o not shown, for the mi proper circulation of the cooling medium. The fluid circulated through the humidiiier may be cooled if deemed desirable and renewed by means of a first water source.

At the end of the period of time when the m process of conditioning air is no longer desirable or necessary, the supply of 'cooling water may be shut oi in the coils 18 and 36 and the heater 35 may be turned on. When this' heater. has .imparted to the brine solution a temperature of approximately F., the damper 26 leading to the humidifier may be closed, and the damper 24 leading to the atmosphere may be opened, the blower 12 is started and a supply of freshair blown through the 13 to absorb water is considerably increased. vIn

View of this condition the air contactingthe.

heated dehydrating solution will absorb water therefrom and this air and water will be discharged from the chamber 10, which is now acting as a dehydrator, to theV atmosphere. When a sutiicient amount of 'water has been removed from the dehydrating solution to bring it to the desired concentration,

lthe heater. 35 may be shut olf and the pumpy 33 and the blower 12 may be shut down and cooling water run-through the coils and 36 a suiiicient length of time to cool the fluid a desired amount. When this is done this system is ready to operateagain as an air conditioning device.

The operation of the apparatus just de scribed contemplates its use in the summer time when the outside air has characteristics ,of-temperature and humidity too high for considerations of health and comfort. In the winter time, however, for considerations of health and comfort, it is necessary yto raise both the temperature and humidity of air in order to impartv thereto characteristics of temperature and humidity which will place it within the healthful comfort range. The apparatus herein described is readily adapted to perform this operation for the incoming tion have been described in some detail but itis to be understood that changes, additions,

substitutions and omissions may be made thereinwithin the spirit of the invention as defined by the appended claims.

1. In, an air conditioning apparatus designed for intermittent use and having adehumidifying chamber, a humidifying chamber and a brine storage tank, aheater disposed within said brine storage tank adapted to heat said brine for reactivation purposes and means to circulate said heated brine through said dehumidiying chamber and contact it with a blast of air whereby excess water is removed from saidv brine.

2. The method of intermittently conditioning air which includes the steps of contacting said air successively with a dehumidiying and humidifying iiuid for a period of time and reactivating said dehumidifying fluid by raising its temperature and contacting it with a blast of air. l

3. The method of intermittently conditioning air which includes thesteps of contacting said air successively with a dehumidifying and humidifying Huid for a period of time and reactivating said dehumidifying `fiuid by raising its temperature and spraying said heated fluid through a current of air.

4. An air conditioning apparatus designed for intermittent operation and having a dehumidifying chamber, a humidifying 'chamber and a brine storage tank, a heater located in said brine storage tank to raise the temperature of said brine, and means to spray said heated brinethrough a current of air in said dehumidifying chamber and a conduit associated vwith said chamber adapted to carry the contacted air and water absorbed thereby to the atmosphere.

HENRY O. FORREST. LEE VAN HORN. 

